Defensins and the convergent evolution of platypus and reptile venom genes

• DOI: 10.1101/gr.7149808
• Publication Date: 2008-05-08T01:35:41Z
• Authors: Camilla M. Whitti...; Anthony T. Papenfuss; Paramjit Bansal; Allan M. Torres; Emily S.W. Wong; Janine E. Deakin; Tina Graves; Amber Alsop; Kyriena Schatzkamer; Colin Kremitzki; Chris P. Ponting; Peter Temple-Smith; Wesley C. Warren; Philip W. Kuchel; Katherine Belov
• Keywords: Platypus; Convergent evolution; Monotreme; Mammal; Molecular evolution

When the platypus ( Ornithorhynchus anatinus ) was first discovered, it thought to be a taxidermist’s hoax, as has blend of mammalian and reptilian features. It is most remarkable mammal, not only because lays eggs but also venomous. Rather than delivering venom through bite, do snakes shrews, male platypuses have venomous spurs on each hind leg. The genome sequence provides unique opportunity unravel evolutionary history many these interesting While searching for sequences antimicrobial defensin genes, we identified three defensin-like peptide (OvDLP) which produce major components venom. We show that gene duplication subsequent functional diversification beta-defensins gave rise OvDLPs. OvDLP genes are located adjacent share similar organization structures. Intriguingly, some species lizards venoms containing molecules called crotamines crotamine-like peptides. This led us trace origins other reptile Here several evolved separately in reptiles. Convergent evolution repeatedly selected coding proteins specific structural motifs templates molecules.